Fitting and method for manufacturing a fitting

ABSTRACT

A fitting for connecting pipes together. The fitting includes a press-fit connection including a ring-shaped seat configured to receive at least one of sealing and holding elements. The fitting is configured to be sealingly connected to an inserted pipe end. A threaded connection is configured to be connected to a pipe by a thread on the threaded connection. The fitting is a single piece and is devoid of weldments.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional Application claiming benefit to Non-Provisionalpatent application Ser. No. 11/392,124, filed on Mar. 29, 2006 thedisclosure of the application is being incorporated by reference herein.

BACKGROUND AND SUMMARY

The present invention relates to a fitting for the connecting of pipes,comprising a press-fit connection provided with a ring-shaped seat forsealing and/or holding elements and which can be sealingly connected toan inserted pipe end by means of cold forming, and a threadedconnection, which can be connected to a pipe by means of a threadedconnection, as well as a method for manufacturing a fitting.

A method for manufacturing a metallic press-fitting element is knownfrom DE 100 29 479 in which a solid or hollow bar is produced as thestarting material for the press-fitting element that is machined. Thisway of manufacturing a press fitting is relatively costly, in particularthe machining method produces waste products.

A method for the manufacture of press fittings is known from DE 43 36261 in which a blank is initially deflected in a die and then the blankis upset to form circular grooves at various places. The wall sectionsare then rolled dimensionally accurate with a roller. This method canindeed be used to produce press fittings for a press-fit connection.Other connections, however, cannot be produced with this method.

A press-fittable fitting is known from DE 39 19 496 in which severalconnecting pieces are provided on one cast or pressed body. Theseconnecting pieces are formed as press sections, which are connectable toa pipe end by means of pressing, wherein the connecting pieces arecemented or welded to the body. The mating of the connecting pieces tothe body to create a fitting is relatively costly, however.

It is thus the object of the present invention to create a fitting and amethod for manufacturing a fitting which facilitate the effectiveproduction of a fitting with different connection types.

This object is achieved by a fitting with the features as claimed inclaim 1 as well as a method with the features as claimed in claim 5.

The fitting according to the invention comprises a press-fit connection,on which there is formed a ring-shaped seat for sealing and/or holdingelements and which is connectable to an inserted pipe end by means ofcold forming. It also comprises a threaded connection, which isconnectable to a pipe by means of a threaded connection, wherein thefitting is produced in a single piece by means of forming. The need tocombine different sections by means of joining, such as cementing orwelding, is thus avoided. The different connection types formed by athreaded connection or a press-fit connection can be produced by meansof a few steps of a method. Depending on the requirements, the walls areshaped and thickened by means of forming in order to obtain acorresponding fitting profile with only minimal use of material.

Preferably, a polygon is formed adjacent to the threaded connection,preferably in the shape of a hexagon. Thus the fitting can be fixed tothe threaded connection during assembly by means of known tools. Thethread can be created as internal thread or external thread.

The fitting is made preferably from a material with good cold formingproperties, such as copper or steel. To ensure good ductility, copperwith a fineness of over 99.8% can be used, such as CO-DHP.

According to the method according to the invention, a pipe section ispressurized and formed on one end to create a press-fit connection witha smooth-walled seat for inserting sealing and/or holding elements, anda middle section is formed to create a pipe-shaped polygon whilethickening individual sections, wherein a thread is subsequently rolleddown or cut into a second end of the pipe section to create a fittingwith a press-fit connection and a threaded connection. In the section ofthe thread, the wall thickness can also be thickened previously byforming, depending on the material thickness of the starting material.Forming can thereby take place both at room temperature as well as in aheated state.

The hydroforming method is preferably used to form the pipe section, inwhich forming takes place under pressure with a fluid. This formingtechnique is gentle on the material and permits both contour changes aswell as material thickening. Cold forging can also be used, depending onthe geometry of the part.

Other aspects of the present disclosure will become apparent from thefollowing descriptions when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first embodiment of a fitting according to the invention,and

FIG. 2 shows a second embodiment of a fitting.

DETAILED DESCRIPTION

A fitting 1 contains a press-fit connection 2, which contains aring-shaped outward projecting bulb 3, by means of which an open seat 4is created, in which a sealing ring can be inserted. A first cylindricalsection 5 is created at the end of press-fit connection 2 and a secondcylindrical section 6 is formed on the side of the bulb 3 facing themiddle which can be formed by means of a pressing tool, in order to joinan inserted pipe end permanently with the fitting 1.

The fitting 1 contains a threaded connection 10 on the side opposite thepress-fit connection 2, which has a greater material thickness thanpress-fit connection 2. The threaded connection 10 has an externalthread 11, adjacent to which there is a polygon 7. The polygon 7 takesthe shape of a hexagon and contains on its outside circumference severalsurfaces 8 arranged in an angle which are spaced from each other byedges 9.

In the embodiment of a fitting shown in FIG. 2, a modified press-fitconnection 2′ is created, in other respects, however, the fitting issimilar to the one shown in FIG. 1. The press-fit connection 2′ containsa ring-shaped seat 3′, which is U-shaped in cross-section and isterminated on the edge side by means of a web 5′ that extends radiallyinward. The seat 4′ is largely rectangular and is used to seat sealingand holding elements, like a cutting ring. In other respects, thepress-fit connection 2′ can, however, be formed radially inward from theoutside by means of pressing tools, in order to provide a permanentconnection with an inserted pipe end.

The method used to produce the fitting takes place by means ofhydroforming. In this method, a pipe section is pressurized and formed.In the area of the press-fit connection 2 or 2′ the correspondinggeometry is produced, wherein the press-fit connection 2 and 2′ isformed smooth-walled with a more or less uniform wall thickness. On theopposite side the material is thickened by means of upsetting for thethreaded connection 10 and the polygon 7 and the polygon contour iscreated. After the blank is finished, the external thread 11 is rolledor cut in. The method used for production can also take place by meansof cold forging.

In the illustrated embodiments, an external thread 11 is provided oneach threaded connection 10. It is, of course, also possible to providefor internal threads.

The fitting 1 is made preferably of high-purity copper, wherein othermetallic materials, such as copper alloys or steel can also be usedwhich are correspondingly formable.

Although the present disclosure has been described and illustrated indetail, it is to be clearly understood that this is done by way ofillustration and example only and is not to be taken by way oflimitation. The scope of the present disclosure is to be limited only bythe terms of the appended claims.

1. A fitting for connecting pipes together, the fitting comprising: apress-fit connection including a ring-shaped seat configured to receiveat least one of sealing and holding elements and which is furtherconfigured to be sealingly connected to an inserted pipe end; a threadedconnection which is configured to be connected to a pipe by a thread onthe threaded connection; a middle section formed as a tubularpolygonal-shaped element and located adjacent the threaded connection;the middle section includes a plurality of individual portions which arethickened relative to a remaining portion of the middle section, theremaining portion being located between the thickened plurality ofindividual portions; and wherein an adjacent section contiguous to oneof the individual portions is the threaded connection.
 2. The fitting asclaimed in claim 1, wherein the fitting is made from a material selectedfrom the group consisting of copper, copper alloys, and steel.
 3. Thefitting as claimed in claim 1, wherein the fitting is made from copperhaving a purity of over 99.8%.
 4. The fitting as claimed in claim 1,wherein the polygonal-shaped element is shaped as a hexagon.
 5. Thefitting as claimed in claim 1, further comprising an additional adjacentsection contiguous to one of the individual portions, such additionaladjacent section being a cylindrical section.
 6. The fitting as claimedin claim 5, wherein the fitting is made from a material selected fromthe group consisting of copper, copper alloys, and steel.
 7. The fittingas claimed in claim 5, wherein the fitting is made from copper having apurity of over 99.8%.
 8. The fitting as claimed in claim 1, wherein thefitting is formed as a single piece devoid of weldments.